Node-Qt: Build native apps using Node.js + Qt (Windows, Mac, Linux)

https://github.com/arturadib/node-qt

by arturadib • 14 years ago

79 26 14 years ago

github.com

mirsadm• 14 years ago

This seems to describe a large portion of javascript based frameworks:

This is a list of common errors when experimenting with Node addons, and their possible solutions: "Out of memory"

arturadib9• 14 years ago

Hi, OP here. As explained that message happens when you mess something up in the C++ bindings, not because of JavaScript actually running out of memory.

arturadib9• 14 years ago

Hi, OP here. For folks who prefer HTML5 APIs, I'm also working on a layer that translates these Qt APIs into HTML5 primitives (like Canvas and AudioContext):

http://news.ycombinator.com/item?id=3816870

(There are some neat demos there :))

buu7003• 14 years ago

Wait, so what Node-Qt and Node-Five would both allow you to use exactly the same code?

arturadib9• 14 years ago

Not the same, but sometimes similar. (For example the QPainter API is similar to the Canvas 2D API, etc).

Node-Five is for folks who are more familiar/prefer HTML5 APIs over Qt's proprietary API.

ing33k• 14 years ago

God job . Will definitely give a try , as I have some experience in both of them .. I always wanted to try qt php bindings, but even running the example apps was difficult .

Thanks to NPM :)

tferris• 14 years ago

OT but regarding the current native app hype (especially in the mobile space): I still don't like native apps except my browser, my editor, the shell and some legacy software (Office and Adobe CS). I don't like updating 30 apps a week on my Android. But it's more than a trend I guess?

arturadib9• 14 years ago

Node-Qt apps are really semi-native since the app itself is written in JavaScript. So you can easily make your app auto-updating, just like a web app. (iOS is an exception due to Apple's restrictions, unless they're OK with QtWebKit which I doubt).

WayneDB• 14 years ago

Web apps are the hype. Native apps have always been the standard.

Your labeling of Office and Adobe CS as "legacy" is just wishful thinking.

iamleppert2• 14 years ago

Nice. Last time I looked at Qt bindings for Node, it didn't support async and used the main node thread to run the UI on (OSX seems to require Qt use the main thread to draw UI on).

Care to elaborate how you got around this? I tired several different things and couldn't get it done.

arturadib9• 14 years ago

Some Qt APIs are inherently asynchronous (like QHttp) but the graphics-related ones I'm binding to are not (like QPainter).

So the situation is analogous to the DOM in web browsers. The calls are synchronous and run in the main thread. As the web has taught us though, single-threads and blocking graphics calls can go a long way :)

iamleppert2• 14 years ago

True, but Qt specifically (as well as many OS such as Mac OSX) do not allow running of the GUI in anything but the main thread. This is due to the fact that (from what I've read) graphics drivers are not thread safe.

Just wondering how you got around this...I see you're using processEvents in QApplication.

from http://doc.qt.nokia.com/4.7-snapshot/thread-basics.html:

GUI Thread and Worker Thread As mentioned, each program has one thread when it is started. This thread is called the "main thread" (also known as the "GUI thread" in Qt applications). The Qt GUI must run in this thread. All widgets and several related classes, for example QPixmap, don't work in secondary threads. A secondary thread is commonly referred to as a "worker thread" because it is used to offload processing work from the main thread.

DaNmarner• 14 years ago

Why the dependency for Python?

arturadib9• 14 years ago

That comes from node-gyp (Node's addon build tool)

vier• 14 years ago

it's a build dependency not a runtime dependency

optymizer2• 14 years ago

So... this allows us to run webservers that call Qt methods? Why would anyone do that?

tlrobinson• 14 years ago

It allows you to call Qt methods from JavaScript. You don't need to run Node as a webserver.

optymizer2• 14 years ago

Don't they have QtQuick or QtScript for that?

firefoxman1• 14 years ago

In the sample on that page, it says:

   // Prevent objects from being GC'd
   global.app = app;
   global.window = window;

Why do you need to do that? I thought that as long as there were still references to an object, it isn't GC'd.

arturadib9• 14 years ago

Yeah it's just in case there are no surviving references to those vars. For example in the hello world code app gets GC'd unless it's in a callback in setTimeout().

artyyouth• 14 years ago

From Qt5 "Lighthouse" would replace C++ as the main development method, and the Qt Quick language in Lighthouse is just a JavaScript extended language, IMHO, this project is just another re-invention of the wheel...

And on desktop, we already have state-of-the-art web browser Chrome, why bother using this to write HTML5 Canvas based app?

Node-Qt: Build native apps using Node.js + Qt (Windows, Mac, Linux)

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